LUX and lumens
 

Are they the same thing?

I am looking at a Sigma Karma Pro light that claimes it has "35 LUX" another light claims to have "1000 lumens". Is LUX short for lumens? Will the light that has 1000 lumens produce more light that the light that produces 35 LUX?

buddy

I think you should go search the definitions for yourself. My take on the terms is that LUX requires that the light produce a given amount across an a given area.

The "lumen" is a measure of light intensity for a given "point" that the light beam is collected. The whole thing is voodoo - man - watch out for zombies......

I actually went out re-read primers on "wave theory" and quantum theory to "see" if i could ever understand what light "is." - I don't.

In any case - the most important attribute of a bicycle light is how it illuminates the path or object you are encountering while moving. (not so important if you are standing still) In "theory" the power of a light in not as important as how its beam is projected on the objects you need illuminating.

Good Lux with understanding my meaning.

Lumens is the total light emitted from a source.
Lux is the intensity per area of light striking a surface.
So if you had a spotlight and a floodlight with the same lumen rating, then measured the lux on one square meter of a surface directly in the center of the beam, 50 feet away, the spotlight would be putting out a higher lux than the floodlight on that surface.

No they are not the same. Lumens are the total light emitted from the source. It is measure best by a very expensive sphere where all the light are trap and then measure.

Lux is the measurement of lumens per square meter. This reading can vary depending on the reflector and how it spread out the beam. If you have a reflector that is concentrated to one square meter at a given distant, then that Lux measurement will be more than the same light source when spread out widely using a different reflector. To make matter worst, many light manufactor will claim much higher lumens rating than what the light is really putting out.

Colleen gets the cigar.

Also, Lumens, being the total energy, is constant for a given light and setting, whereas Lux varies with distance from the source, of course, dimmer father away.
Then the question is what Lux value and at what distance from the light is it specified?

So, by themselves, neither Lumens nor Lux is a good way of comparing lights for how good it will be for riding. The beam pattern, if well focused might look good as having a high Lux value, but be too much of a spotlight when on the bike.
The best way to compare is to try it, and/or search for reviewers beam pattern photos.

So I have two lights, a 600 lumen that has a nice, wide beam and a 200 lumen that has a focused spotlight beam. The 200 lumen light is noticeably brighter. You can see its spot well defined within the light that comes from the 600. Also, if you stand in front of the bicycle and look back, the 200 lumen looks brighter. However, it's obvious that the 600 is putting out much more light, it's just spread around nicely. Therefore, from what I'm reading here, the 600 has more lumens and the 200 is greater in lux. Am I in the ballpark?

That's right.
I also have a flood and spot combo which is good for riding on trails.

Interesting facts:
full sun at noon is about 120,000 Lux
a full moon is about 0.25 Lux
http://en.wikipedia.org/wiki/Daylight